point indicator

例句：

1. 1. The engineer used a pointer to indicate the correct answer on the board.
   工程师用一个指针在黑板上指出正确的答案。
2. 2. The new point indicator system is designed to improve efficiency.
   新的点指示系统旨在提高效率。
3. 3. The teacher used the pointer to help students understand the concept of distance.
   老师用指针帮助学生理解距离的概念。